The 37-year-old, best known for being the frontman of Boyzone, makes his big screen voice-over debut in Postman Pat: The Movie, as the postie's singing voice. He will also star in romantic comedy Goddess alongside British actress Laura Michelle Kelly.

"I'd like to do a lot more film work. I've been working on that for 15-20 years or so," he said.

"(There's been) a lot of rejection. I read for Moulin Rouge in New York, I read for King Arthur with Antoine Fuqua, The Hobbit more recently. A lot of setbacks and knockbacks, but it's starting to slowly happen now. People are starting to believe in me, which is really refreshing."

Ronan said his "passion" for film and acting kept him on the chase for more big screen parts.

"It's taken some time. I've met with a lot of casting people around the world for the last 10-12 years, and just nothing happened," he continued.

"And now, all of a sudden, one director starts to believe in me and the world starts to slowly realise maybe they can put me in a film. It's nice. You've got to work hard for stuff."

:: Postman Pat: The Movie is in cinemas now. Goddess will be released on June 27.